Military bomb such as shell, bomb, land mine, and naval mine are normally filled with an explosive in a steel casing. In particular, chemical weapons are filled with an explosive as well as a chemical agent hazardous to a human body. Examples of the chemical agents used include, for example, mustard and lewisite hazardous to the body.
Treatment of chemical weapons by blasting has been known as a method of processing and detoxifying such chemical weapons. The treatment by blasting has advantages that it does not demand disassembling operation, allows treatment not only of favorably preserved bombs but also of the bombs that are difficult to disassemble because of aged deterioration and deformation, and that most of the chemical agents therein are decomposed under the ultrahigh temperature and ultrahigh pressure generated by explosion. Such a processing method is disclosed, for example, in Patent Document 1.
The blasting is frequently performed in a tightly sealed vessel, for prevention of leakage of the chemical agents to outside and adverse effects on environment such as noise and vibration of blasting. It is also advantageous to blast a bomb in a tightly sealed vessel under vacuum, keeping a negative pressure in the vessel even after treatment, for more reliable prevention of the outward leakage of the chemical agents.
[Patent Document 1] Japanese Unexamined Patent Application No. No. 7-208899.
However, when a bomb is blasted by the method described in the Patent Document 1, the vessel should be rigid enough to prevent noise and to withstand the impact by explosion. However, solid fragments, for example, from the bomb shell of weapon scatter at a significantly high velocity by explosion and collide to the vessel, often causing damages on the internal wall of the vessel. Accordingly, the vessel should be replaced occasionally, because it is damaged significantly after several treatments. The vessel is larger in size and weight, and thus, is not easy to replace.
Since establishment of the chemical weapons ban treaty, there is an ever-increasing demand for demolition of chemical weapons all over the world. For example, the Japanese Government ratified the chemical weapons ban treaty and has an obligation under the treaty to demolish chemical weapons left in China by the old Japanese Army. According to the “Outline of the Project for the Destruction of Chemical Weapons abandoned by the old Japanese army” issued in October 2002 by the Project Team for Destruction of Abandoned Chemical Weapons, Cabinet Office, there are estimated, approximately 700,000 chemical weapons still abandoned in all areas of China. In designing the processing facility, the report says that a facility should have a processing capacity of 120 bombs per hour, assuming that 700,000 bombs are processed in three years.
Accordingly, for efficient low-cost processing of a number of the abandoned chemical weapons by the blasting described above, there is a strong demand for a method of blasting bombs in a tightly sealed vessel without damage therein that can reduce the labor and time for exchanging the vessel. In addition, there is a strong need for a highly efficient method of processing many weapons at the same time.